A biopsy is used to detect the presence of cancer cells in the prostate and
to evaluate how aggressive cancer is likely to be. Thanks to an array of biopsy
techniques and new tools to interpret the results, doctors are better able to
predict when cancers are slow-growing and when they’re likely to be aggressive.
That information, in turn, can help you and your doctor choose the best course
Before having a prostate biopsy performed, most men have undergone other
tests for prostate cancer. PSA tests, for example, measure a substance called
prostate-specific antigen in the bloodstream. Abnormally high levels may signal
the presence of cancer. Because PSA levels are higher in men with larger
prostate glands, doctors also use a test called PSA density, which relates PSA
level to the size of the gland. A digital rectal exam, in which the doctor
inserts a gloved lubricated finger into the rectum, is used to detect unusual
bumps or hard areas on the prostate that might be cancer. If these tests raise
concern, the next step is a prostate biopsy.
The goal of a biopsy is to remove small samples of prostate tissue so that
it can be examined under a microscope for signs of cancer. In the most commonly
performed procedure, a needle is inserted through the wall of the rectum into
the prostate gland, where it removes a small cylinder of tissue.
The biopsy needle can also be inserted through the skin between the rectum and
the scrotum, an area called the perineum. In order to sample tissue throughout
the gland, 12 or more core samples are typically removed from different parts
of the prostate. To guide the procedure, doctors view an ultrasound image of
the gland on a video screen as they manipulate the needle.
Most biopsies are performed in an urologist’s office. The procedure, which
only takes about 15 minutes, may cause some discomfort but not serious pain.
Your doctor may prescribe an antibiotic medicine to take one day before and a
few days after the procedure. You may experience a little soreness afterward,
and you may notice blood in your urine or semen for a few weeks.
Deciphering the Results
Biopsied tissue is sent to a laboratory, where a pathologist views the cells
under a microscope. When healthy cells become cancerous, their appearance
begins to change. The more altered the cells look, the more dangerous the
cancer is likely to be.
The results from a prostate biopsy are usually given in the form of the
Gleason score. On the simplest level, this scoring system assigns a number from
2 to 10 to describe how abnormal the cells appear under a microscope. A score
of 2 to 4 means the cells still look very much like normal cells and pose
little danger of spreading quickly. A score of 8 to 10 indicates that the cells
have very few features of a normal cell and are likely to be aggressive. A
score of 5 to 7 indicates intermediate risk.